How to display a price if found and another if not found? AX 2012 - axapta

Question

I have two tables created by me. I created a form for the second table. I have to add testing data to the form so the Price field will be populated automatically based on the following logic:
check if the ItemId is available in the first Table
If found, display the price of the item from the first table
If not found, display the standard price of the item (Product information management/ Common > Relased products, select a product and on Sell Tab > Price unit.
I tried the following display method but when I choose the ItemId it shows me only 1 or only the first table value and the rest Items which are not found the value 0.
display Price price()
{
HC_ClubAxEx1 hcex1;
InventTableModule inventTableModule;
select PriceUnit from inventTableModule;
if (this.ItemId == hcex1.ItemId)
{
this.Price = hcex1.Price;
select Price from hcex1;
}
else
{
this.Price = inventTableModule.PriceUnit;
}
return this.Price;
}
Please help

Answer 1

In my opinion you need to check the display method:
This command, return always the first value:
select PriceUnit from inventTableModule;
display Price price()
{
HC_ClubAxEx1 hcex1;
InventTableModule inventTableModule;
// In the same way you need to select hcex1 Table by query:
//Example:
select hcex1 where hcex1.MyField == 'yourValue...'
if (this.ItemId == hcex1.ItemId)
{
// Try to check in debug mode, if the current hcex1 record follow your logic
this.Price = hcex1.Price;
// The below code line it's not necessary for you.
//Need to select the record before to use it
//select Price from hcex1;
}
else
{
// select PriceUnit from inventTableModule;
// You need to create a right select
//Example below:
// Need to select the record by
//current ItemId or by your logic.
select PriceUnit from inventTableModule
where inventTableModule.ItemId == this.ItemId;
this.Price = inventTableModule.PriceUnit;
}
return this.Price;
}
Following the other people, I try to recommend you to read these guides:
https://learn.microsoft.com/en-us/dynamicsax-2012/developer/select-statement-syntax
https://dynamicsaxswapt.wordpress.com/2015/10/01/select-statements-in-ax-2012/
https://learn.microsoft.com/en-us/dynamicsax-2012/developer/select-statement-examples
Have a nice day.